I have a 2011 4 cyl automatic
I washed under body and frame with power washer
I noticed the next day the engine light was on and took it to my
mechanic, he ran the code and then entered it into a web site he has
which said that most common problem was water in the connection
going to the fuel ox sensor.
sure enough when he unpluged the large plug on frame water poured out
he then blew it out the dryed it with a heat gun then reset the computer
light stayed out all day but then this morning engine light back on
i unpluged the connector again and put somemore electrical grease on it
then took neg off battery for a few minutes then started the truck and
light was off,drove truck a couple miles and engine light still off.
later started truck and engine light back on
anyone have any suggestions.i give up.:

 

There is more than one connector.....................
And it may be a different code now

 

got any ideal where the other plug is located under the truck
i looked today and couldn,t find another one
also do you think unhooking the neg cable to reset computer was good enough
or i need to have it reset by my mechanic

 

got any ideal where the other plug is located under the truck,i looked
today but only seen the large on on rail frame by the gas tank
i do think it is a wet issue account had no problem until washed the underside of truck

 

There is another connector under the drivers seat thru the floorpan, there were a few TSBs on that one I believe, but I thought they changed connector style by 2011.

I assume he means the O2 sensors, have you checked those connectors?
One on the exhaust pipe by the engine and another one after the Cat converter

Yes, disconnecting the negative battery cable for 5 minute will reset computer the same as a reader will do, it won't clear history codes, but that is a good thing :)

I would get the computer read again, it is free at most auto part stores and this time write down the codes, all of them.

Everything mechanic did was based on that code(and it didn't work) and you have not posted what it was, so I assume you don't know it??

 

cleaned them all still getting code po453

 

Ford Ranger code P0453 - Evaporative Emissions Control System Pressure Sensor High Input

So you were probably checking the wrong things

Back by the fuel tank there is the fuel tank pressure(FTP) sensor, either that sensor is bad or the wires are.
Could even be a plugged up equalizer hose( a drain hose).

When you start the engine the computer seals the fuel tank and monitors its pressure with the FTP sensor, it then cycles and tests pressure now and then, if it reads a higher voltage from sensor it sets the code P0453

Good read here on testing wires and sensor:
P0453 DTC Evaporative Emissions Control System Pressure Sensor High Input

On the newer Rangers I think FTP sensor is accessible with spare tire lowered but just guessing.

 

so the ftp sensor is on the round tank up above the rearend.
do you think when i got water in the big plug inside the frame rail on drivers
side even though we dried it out and engine light stayed out for a day it might
have shorted out the ftp sensor

 

hate to take to a dealer although they said ever what caused the sensor to fail
might be covered under the 60,000 mile warranty which i kind of dought.
dealers normally cost a arm and a leg although i don,t know that my regular meachanic can fiquire it out except by trail and error which can also cost a lot

 

Did you read the whole link I posted above?

It tells you how to test FTP sensor.

So buy a $25 meter and test the sensor and the wires as stated.
That $25 will save you hundreds of dollars down the road, there are very few sensors or controls that can not be tested with a Volt or OHM meter